<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>停止定时器</button>
    <script>
        // let btn=document.querySelector('button');
        // let Settime=setTimeout(function(){        //setTimeout()只调用一回;
        //     alert('416全体起立！！！！');
        // },2000);
        // btn.addEventListener('click',function(){
        //     clearTimeout(Settime);
        // })

        //设置定时器
        const time=setTimeout(function(){
            alert('416全体起立！！！！');
        },1000);
    </script>
</body>
</html>